People treated for cancer confront much adversity, but there are also reports that the experience changes many people's lives for the better. At present, little is known about whether such positive changes can be enhanced by psychosocial interventions or what factors might mediate or moderate the process. Even less is known about whether growth experiences might relate to beneficial physiological changes that could reduce the risk of later disease recurrence. With prior funding we examined cross-sectionally 223 early-stage breast cancer patients and found widespread evidence of perceived positive contributions from having been diagnosed with cancer. Positive contributions in this sample related to lower levels of emotional, social, and sexual disruption. We also tested a 10-week Cognitive Behavioral Stress Management (CBSM) program in a second sample of early-stage breast cancer patients (n = 132, final followups continuing). This intervention proved to induce a sense of positive contribution above the levels that arose spontaneously in the control group. The increase remains in place 9 months after the intervention (i.e., 1 year post-diagnosis). This enhancement of positive contributions in the therapy group mediated lower levels of subsequent distress. We have also conducted pilot work in this sample to develop an immunologic assessment battery, with measures that characterize cellular immune functions and related cell-signalling cytokines. In the proposed work we will evaluate CBSM among White, Hispanic (both English- and Spanish-speaking), and Black women who are newly diagnosed with and treated for early/middle stage breast cancer (Stages I-III). The proposed project will further examine impact of positive contributions (as well as distress), by examining the effects of CBSM in a variety of life spheres at 3 months and 9 months after the intervention. The intervention is hypothesized to improve psychosocial adjustment and foster a sense of positive growth, foster a more rapid return to pre-diagnosis quality of life, indexed by levels of positive and negative mood, fatigue symptoms and sleep quality, and disturbances in social and psychosexual functioning. We also will examine how changes in these spheres are paralleled by changes in aspects of immune functioning relevant for future risk of disease recurrence, including lymphocyte subpopulations; lymphoproliferative responses to anti- CD3; interleukin-2 (IL-2) and interferon-gamma (IFN-y) production during lymphoproliferative challenge; and recombinant (r)IL-2- and rIFN-y-stimulated natural killer cell cytotoxicity to K562 targets, and three breastcancer lines, MB453 SKBR3, and MCF-7.